A good case for Invisible XML (topic of the week at Balisage), but
I'll leave someone else to flesh it out.

of
https://balisage.net/Proceedings/vol27/html/Kay01/BalisageVol27-Kay01.html#d1
0153e637
instead, the paper says

that is, it wraps each of the array members into a parcel and processes
each one separately.

But I don't grasp how that initiates "the action of the default template
rule here is to construct a new array or map from the values returned by
the selected template rules"?

How are the arrays or maps created, doesn't that require use of xsl:map
and xsl:array?

Is <xsl:mode on-no-match="shallow-copy-all"/> behaviour definable with
current or future XSLT elements?